Motley Fool put out an article (available on Yahoo) that claims the jump was because of earnings yesterday. But if I remember right earnings yesterday came out before the close. A beat of .02 compared to expectations doesn't seem enough to warrant a 33% gain.
The Motley Fool article showed up on Yahoo after the gains were already in for the day, although I suppose it could have been on the Fool website earlier. I don't follow the Fool.